Composition for extrusion-molded ceramic bodies comprising a cellulose derivative of certain median particle length

Abstract

A composition which is suitable for extrusion molding comprises a) a ceramic-forming material, and b) a cellulose derivative that has a median particle length of from 110 to 300 micrometers. Advantageously a cellulose ether is used that has been obtained by providing a moist cellulose derivative having a moisture content of from 35 to 90 percent, based on the total weight of the moist cellulose derivative, and drying-grinding the moist cellulose derivative in a gas-swept impact mill to a median particle length of from 110 to 300 micrometers.

1 . A composition comprising
 a) a ceramic-forming material, and   b) a cellulose derivative having a median particle length of from 110 to 300 micrometers.   
     
     
         2 . The composition of  claim 1  wherein the cellulose derivative has a median particle length of from 120 to 270 micrometers. 
     
     
         3 . The composition of  claim 1  wherein the cellulose derivative is obtainable by providing a moist cellulose derivative having a moisture content of from 35 to 98 percent, based on the total weight of the moist cellulose derivative, and drying-grinding the moist cellulose derivative in a gas-swept impact mill. 
     
     
         4 . The composition of  claim 1  wherein the cellulose derivative is obtainable by mixing a cellulose derivative with a liquid to provide a moist cellulose derivative having a moisture content of from 35 to 98 percent, based on the total weight of the moist cellulose derivative, and drying-grinding the moist cellulose derivative in a gas-swept impact mil. 
     
     
         5 . The composition of  claim 1  wherein the cellulose derivative is a cellulose ether. 
     
     
         6 . The composition of  claim 1  wherein the ceramic-forming material is an alumina or a precursor thereof, silica or a precursor thereof, an aluminate, aluminosilicate, alumina silica, feldspar, titania, fused silica, aluminum nitride, aluminum carbide, kaolin, cordierite, mullite, clay, bentonite, talc, zircon, zirconia, spinel, silicon carbide, silicon boride, silicon nitride, titanium dioxide, titanium carbide, boron carbide, boron oxide, borosilicate, soda barium borosilicate, a silicate, a sheet silicate, a silicon metal, soda lime, zeolite, barium titanate, lead titanate zirconate, aluminium titanate, barium ferrite, strontium ferrite, carbon, ground glass, a rare earth oxide, or a combination of two or more of such inorganic materials. 
     
     
         7 . The composition of  claim 1  wherein the cellulose derivative is present in dried and ground form. 
     
     
         8 . The composition of  claim 1  wherein the cellulose derivative is a methylcellulose with a methyl degree of substitution DS methyl  of from 1.2 to 2.2; or a hydroxypropyl methylcellulose with a DS methyl  of from 0.9 to 2.2 and an MS hydroxypropyl  of from 0.02 to 2.0; or a hydroxyethyl methylcellulose with a DS methyl  of from 1.15 to 2.3 and an MS hydroxyethyl  of from 0.03 to 1.0; or a hydroxyethyl cellulose with an MS hydroxyethyl  of from 1.2 to 3.0. 
     
     
         9 . A process for producing an extrusion molded body comprising the step of
 A) mixing a cellulose derivative having a median particle length of from 110 to 300 micrometers with a ceramic-forming material, a liquid diluent and optional additives to produce a pasty mass,   B) optionally passing the pasty mass through a wire screen and   C) subjecting the pasty mass to extrusion molding to produce an extrusion molded body.   
     
     
         10 . The process of  claim 9  wherein the cellulose derivative has been obtained by drying-grinding a moist cellulose derivative having a moisture content of from 35 to 90 percent, based on the total weight of the moist cellulose derivative, in a gas-swept impact mill to a median particle length of from 110 to 300 micrometers. 
     
     
         11 . The process of  claim 9  wherein an extrusion molded body having a honeycomb structure is produced. 
     
     
         12 . The process of  claim 9  wherein the extrusion molded body is subjected to drying and baking or sintering. 
     
     
         13 .- 15 . (canceled)